What is the treatment for cellulitis (inflammation of the skin and subcutaneous tissues) with fever?

Treatment of Cellulitis with Fever

For cellulitis with fever, treatment should begin promptly with antibiotics effective against streptococci (the most common causative pathogens) and, when indicated, staphylococci, with hospitalization for patients with systemic inflammatory response syndrome (SIRS) or other concerning features. 1, 2

Initial Assessment and Antibiotic Selection

• For non-purulent cellulitis with fever, select antibiotics active against streptococci, which are the most common causative organisms 2
• For mild to moderate cases without systemic toxicity, oral options include:
  • Penicillin or amoxicillin (if streptococcal infection is strongly suspected) 2, 3
  • Dicloxacillin or cephalexin (500 mg four times daily) if S. aureus coverage is desired 2, 3
  • Clindamycin for penicillin-allergic patients 2
• For more severe infections with fever, parenteral antibiotics are recommended:
  • Cefazolin IV or nafcillin IV are appropriate first-line options 3
  • For adults: cefazolin 1g every 8h or nafcillin 1-2g every 4-6h 3

MRSA Considerations

• MRSA is not a typical cause of non-purulent cellulitis, and routine MRSA coverage is unnecessary 2, 3
• Consider MRSA coverage only in specific situations:
  • Presence of purulent drainage 1, 2
  • Evidence of MRSA infection elsewhere 2, 3
  • History of injection drug use 2, 3
  • Penetrating trauma 2, 3
  • Lack of response to beta-lactam antibiotics 3
  • Systemic inflammatory response syndrome (SIRS) 2, 3
• When MRSA coverage is indicated, options include:
  • For outpatients: trimethoprim-sulfamethoxazole, clindamycin, or linezolid 3, 4
  • For inpatients: vancomycin IV, linezolid IV/oral, daptomycin IV, or telavancin IV 3

Hospitalization Criteria

• Most patients with cellulitis can be treated as outpatients 2
• Consider hospitalization if the patient has:
  • Systemic inflammatory response syndrome (SIRS) 1, 2
  • Fever with significant systemic toxicity 1, 5
  • Altered mental status 2
  • Hemodynamic instability 2
  • Concern for deeper or necrotizing infection 2
  • Poor adherence to therapy 2
  • Severe immunocompromise 2
  • Failure to respond to outpatient therapy within 24-48 hours 3

Duration of Therapy

• A 5-day course of antimicrobial therapy is as effective as a 10-day course for uncomplicated cellulitis if clinical improvement occurs by day 5 2, 3, 6
• Extend treatment only if the infection has not improved within the initial 5-day period 2, 3
• For more severe infections with fever, treatment may need to be extended until resolution of systemic symptoms 1

Adjunctive Measures

• Elevate the affected area to promote gravity drainage of edema and inflammatory substances 2
• Consider systemic corticosteroids (e.g., prednisone 40 mg daily for 7 days) in non-diabetic adult patients to reduce inflammation and hasten resolution 2
• For abscesses associated with cellulitis, incision and drainage is the primary treatment 1
• Complex abscesses (perianal, perirectal, or at injection sites) require incision and drainage with adjuvant antibiotic therapy, especially when systemic signs of infection are present 1

Common Pitfalls to Avoid

• Don't extend antibiotic treatment unnecessarily beyond 5 days if clinical improvement has occurred 2
• Don't automatically add MRSA coverage for typical non-purulent cellulitis without specific risk factors 2, 3
• Don't fail to recognize signs of deeper infection requiring surgical intervention 1
• Don't underestimate the severity of streptococcal cellulitis, which can cause high fever and systemic toxicity requiring prompt treatment 5
• Don't neglect to consider unusual pathogens in immunocompromised patients or those with specific exposures 7